const axios = require("axios");
const bitcoin = require("bitcoinjs-lib");
const coinselect = require("coinselect");
const split = require("coinselect/split");
const api = prod ? "https://blockstream.info/api" : "http://localhost:3095";
const SATS = 100000000;
const network = prod
? bitcoin.networks["bitcoin"]
: bitcoin.networks["regtest"];
module.exports = async ({ address, amount, feeRate, replaceable, user }) => {
if (!feeRate) feeRate = (await bc.estimateSmartFee(6)).feerate * SATS;
feeRate = Math.round(feeRate / 1000);
const payments = await db.Payment.findAll({
where: {
received: true,
account_id: user.account_id,
network: 'bitcoin',
}
});
const addresses = [...new Set(payments.map(p => p.address))];
const utxos = [];
for (let i = 0; i < addresses.length; i++) {
try {
utxos.push(...(await axios.get(`${api}/address/${addresses[i]}/utxo`)).data);
} catch (e) {
l.error("problem fetching utxos", e.message);
}
}
let targets = [
{
address,
value: amount
}
];
let { inputs, outputs, fee } = coinselect(utxos, targets, feeRate);
if (!inputs || !outputs) {
l.info("utxos", amount, feeRate, utxos.map(u => u.value));
throw new Error("Couldn't find inputs for transaction, check your balance/fee");
}
let psbt = new bitcoin.Psbt({ network });
let total = 0;
outputs.map(({ address, value }) => {
total += value;
if (!address) {
address = payments[payments.length - 1].address;
change.push(address);
}
psbt = psbt.addOutput({
address,
value
});
});
for (let i = 0; i < inputs.length; i++) {
let { txid, vout } = inputs[i];
let nonWitnessUtxo = Buffer.from(await bc.getRawTransaction(txid), "hex");
psbt = psbt.addInput({
hash: txid,
index: vout,
nonWitnessUtxo
});
}
if (replaceable) psbt.setInputSequence(0, 0xffffffff - 2);
feeRate = Math.round(feeRate * 1000);
psbt = psbt.toBase64();
return { tx: psbt, feeRate };
};